1. Technical Field of the Invention
The present invention relates to a fastening device according to the preamble of claim 1 to be utilized in connection with various shelves and racks, stands, article holders and similar means for instance in shops, storages, transporting means and similar.
2. Prior Art
It is prior known to use a structure in the shelves, carriers or similar in which the shelf comprises frame means and therein fixed article supporting means, such as supporting arms, shafts or beams or shelf plates, extending horizontally or in certain angle from the frame means. The frame means form essentially straight body portions i.e. so called vertical pillars, which normally extend upwardly from the floor. Frame means are provided with a plurality of openings, and the supporting arms are normally clamped to the body portion by a hook-like portion or bracket provided in one end of the supporting arm and adapted to be positioned into the opening or openings of the body portion such that the arm is retained and supported by the bracket in the frame and retains the desired position relative to the frame. A slot or loop is normally defined between the bracket means and the arm such that said slot is adapted to receive the thickness of the frame means material. The width of said slot corresponds essentially accurately to the thickness of the material used in the frame, being only slightly wider than it, whereby the brackets are rigidly and accurately clamped to the body portion. Due to the simplicity and rapid assembly of said structure it is very commonly used, and the manufacturers of the shelves do each have a version of their own thereof, in which the shape and thickness of the brackets, the thickness of the frame material and the shape and size of the openings are different.
A disadvantage of the presented solutions has been that the hook-like bracket means of various manufacturers have followed "the standard" of each manufacturer, and thus are not suitable to be used in connection with other shelves. Therefore the users of the shelves have usually been forced to bind themselves to one supplier of the shelves, which may have had a disadvantageous effect to the costs. Furthermore, the clamping means i.e. hooks or brackets meant for one "shelf strength" fit only with one material thickness of the frame means. Thus several hooks designed to different material thicknesses are required, which has caused confusion among the users and even dangerous situations when a shelf has been assembled by using inappropriate hooks. Furthermore, sometimes the shelves may require an adjustment, for instance due to irregularities on the floor and/or slight deflections or inaccuracies in the manufacture of the arms. A prior art hook provided with a slot has not provided any possibility to adjust the position of the arm means, and thus the position has always been determined according to the fact how the slot of the hook and the frame portion fit to each other.
Norwegian patent No. 83485 discloses one improved fastening arrangement. According to that it is possible to adjust the position of the shelf beam by a therein integrated screw means. However, it is still a problem that the means and the shelf frame have to be manufactured to exactly correspond to each other, and they do not suit to be used in connection with other corresponding means. In addition, it is not possible to use the adjustment arrangement described therein in connection with a hook provided with a slot and most commonly used.